Repeat with remaining cannoli. Melt dark and white chocolate separately in microwave or in double boiler.With a spoon, drizzle chocolate in a criss cross design over cannoli, by moving your hand in a back and forth motion. Alternatively, put melted chocolate in a gallon size resealable plastic bag and cut off a tiny hole in the corner. Drizzle over cannoli with a back and forth motion. Allow chocolate to harden.